1. Field of the Invention
This invention relates to clip on spacers for rebars or welded fabric used in structures to space the rebars or welded fabric a specified distance from concrete mold walls.
2. Description of the Related Art
In the past concrete rebars or welded fabric have been held in place by a variety of devices. Some of the devices are for holding the rebars or welded fabric a specified distance above the ground and so have a large ground contacting area to form a stable base for holding the rebars or welded fabric up without the spacer tipping over. Other spacers are used to hold mold walls away from a lattice of intersecting rebars or welded fabric. In this use a large contact area with the wall will leave a large area of the spacer exposed when the mold is removed. The concrete is thereby prevented from filling in the volume against the mold wall in the space occupied by the spacer. It is important to have as small a footprint of the spacers at the mold so that the edges of the poured concrete has more concrete on the outer surface for greater strength and for a better appearance.
Some spacers have clip on portions where two clips on each rebar are very close together such that the spacer can twist or turn on the rebar. These spacers are thus not held sufficiently straight, resulting in variations of spacing distance between the mold wall and the rebars or welded fabric. It is important to have spacers that will stay aligned to hold the mold wall a specified distance from the rebars or welded fabric.
Some spacers have clip on connections, which can come loose during impacts received during the construction process. It is desired to have clips that will stay connected once installed on the rebars or welded fabric.
Strike Tool 31785 64th Ave., Cannon Falls, Minn. 55009, has a pyramid spacer with a C-shaped clip-on portion for engaging rebars.
The pyramid spacers have a pointed tip for contacting the mold walls thus leaving a small footprint on the outer portion of the poured concrete. The pyramid spacers also have a wide base with the clips spaced at the ends of the base for engaging rebars or welded fabric to provide stability against twisting forces such that the pyramid spacer remains oriented to space the rebars or welded fabric at a specified distance from the mold walls. Further the clips on the pyramid spacers have a rebar engaging portion for the rebar or welded fabric to fit into and two arms pressing on the rebar or welded fabric to lock the rebar or welded fabric snugly in place. The pyramid spacers also have a pair of pads at the corners of the base for engaging a perpendicularly crossing rebar or welded fabric to stably hold the pyramid spacers in a plane defined by the intersection of the rebars or welded fabric. Having only one pair of clips makes it easier to install the pyramid spacers.
In another embodiment the cage spacers have a trapezoid body portion and a double apex body portion with pads and clips for engaging the rebars or welded fabric. The double apex embodiment provides more stability of the cage spacer relative to the mold wall by having two contact points. In a further embodiment the cage spacer has two perpendicular double apex portions providing four apexes for engaging the mold wall and defining the plane of contact such that the cage spacer is stable on all axis against the mold wall.
It is an object of the invention to provide a spacer for spacing rebars or welded fabric a specified distance from molds.
It is an object of the invention to provide a spacer that will not come off of the rebars or welded fabric once installed.
It is an object of the invention to provide a spacer that will not twist or turn once installed which will change the distance of the rebars or welded fabric to the mold wall.
It is an object of the invention to provide a small footprint of the spacer at the mold wall.
It is an object of the invention to provide spacers with clips that are easy to install.
It is an object of the invention to provide an inexpensive, reliable and durable spacer.